Matlab – City College of New York

Matlab License

CUNY offers a campus-wide license to MATLAB, Simulink, and all companion products. All faculty, researchers, and students are eligible to download and install these products on their university computers as well as their personally-owned computers.

License prerequisites

You need to have a valid CUNY email address, either in the format citymail or ccny email.
You need to renew license in your Matlab application once a year at the end of November.

Preparation: Mathworks account

If you don’t have a Mathworks account associated with your CUNY email address yet, go to the following URL to create and account:

URL: https://www.mathworks.com/login

Link License

The campus local license administrator will help you to link CUNY site license to your Mathworks account.

Department	License administrator	Email	Phone
Levich Institute	Junjun Mao	jmao@ccny.cuny.edu	212-650-6845
Chemical Engineering	Andrew Eng	aeng@ccny.cuny.edu	212-650-6624

Once your local license administrator gives the license activation code, go to your account at Mathworks website and click on link license:

Installation

Download the installer

Download the Matlab installer from Mathworks.

Run the installer

When you run the matlab installer, choose installation method with “Log in with a MathWorks Account”.

Then Login with your MathWorks account.

After you login, you will be presented with license choice and please select this license

License	Label	Option
1111017		Standard – Individual

Renew the license

The license renewal option is hidden under Help -> Licensing -> Update Current Licenses. You will need to do this every year at the end of November or earl December.

Servers with preinstalled Matlab

Levich Institute and Chemical Engineering department offer following computing resources that have preinstalled Matlab. Matlab runs best on your own computer but the servers fit situation like:

One needs to run prolonged sessions of Matlab jobs
One’s Matlab jobs require memory and CPU more than a personal computer can handle.

Cheme Linux server

Server Name	cheme.engr.ccny.cuny.edu
Operating system	Ubuntu 18.04
CPU	64
RAM	196 GB
Remote Access	ssh, vmhub
Account Application	Junjun Mao <jmao@ccny.cuny.edu>

Poincare Linux server

Server Name	poincare.engr.ccny.cuny.edu
Operating system	Ubuntu 10.04
CPU	32
RAM	128 GB
Remote Access	ssh, vmhub
Account Application	Junjun Mao <jmao@ccny.cuny.edu>
Remark	Scheduled to be upgraded soon

Chemical Engineering Citrix server

Server Name	cheportal.ccny.cuny.edu
Operating system	Windows
CPU	2
RAM	8 GB
Remote Access	https://cheportal.ccny.cuny.edu
Account Application	Andrew Eng <aeng@ccny.cuny.edu>
Remark	This server offers Matlab through non-persistent virtual desktop

Note:

You need City College VPN account to access the server cheme.engr.ccny.cuny.edu and poincare.engr.ccny.cuny.edu by ssh.

Matlab Online

You can run Matlab Online provided by Mathworks within a browser window if you have a Mathworks account with CCNY site license.

URL: https://matlab.mathworks.com/

Learning Matlab

Online resources

Matlab Onramp: Learn the essentials of MATLAB® through this free, two-hour introductory interactive tutorial on commonly used features and workflows.
MIT Open course: Short videos serve as introduction to Matlab programming for beginners.

Matlab books

Physical Modeling in MATLAB by Allen Downey: learn some programming, some modeling, and some simulation in this free book.

MATLAB: A Practical Introduction to Programming and Problem Solving (5^th edition) by Stormmy Attaway: winner of TAA’s 2017 Textbook Excellence Award (“Texty”).

Matlab Quick Reference

The Matlab Work Environment

General Commands

Tip

Some commands have links to syntax details and examples.

Command	Description
clc	Clear Command Window
clear	Remove items from workspace, freeing up system memory
close all	Close all plots
doc function	Display documentation page in Help browser
help	Help for functions in Command Window
ver	Version information for MathWorks products
% some comment text	Comment text
CTRL+C	Abort the current operation
format short	Display 4 decimal places
format long	Display 15 decimal places
disp(‘some text’)	Print some text

Defining Variables

Command	Description
a = 3	Define variable a to be 3
x = [1, 2, 3]	Set x to be the row vector [1, 2, 3]
x = [1; 2; 3]	Set x to be the column vector [1, 2, 3]T
A = [1, 2, 3, 4, 5, 6; 7, 8, 9, 10, 11, 12]	Set A to be a 2 × 6 matrix
x(2) = 7	Change x from [1, 2, 3] to [1, 7, 3]
A(2,1) = 0	Change A2,1 from 5 to 0

Basic Arithmetic

Command	Description
3*4, 7+4, 2-6, 8/3	multiply, add, subtract and divide
3^7	Compute $3^{7}$
sqrt(5)	Compute $\sqrt{5}$
log(3)	Compute natural logarithm $l n (3)$
log10(100)	Compute common logarithm (base 10) $l o g (10)$
abs(-5)	Compute \|-5\|
sin(5*pi/3)	Compute $s i n (5 π / 3)$

Round numbers

Command	Description
floor(-1.5)	-2; Round toward negative infinity
ceil(-1.5)	-1; Round toward positive infinity
fix(-1.5)	-1; Round toward zero
round(-1.5)	-2; Round to nearest decimal or integer

Matrices and Vectors

Command	Description
zeros(12, 5)	Make a 12 × 5 matrix of zeros
ones(12, 5)	Make a 12 × 5 matrix of ones
eye(5)	Make a 5 × 5 identity matrix
eye(12, 5)	Make a 12 × 5 identity matrix
linspace(1.4, 6.3, 1004)	Make a vector with 1004 elements evenly spaced between 1.4 and 6.3
logspace(1.4, 6.3, 1004)	Make a vector with 1004 elements where the log of the spacing is evenly increasing between 1.4 and 6.3
7:15	Row vector of 7, 8, . . . , 14, 15

Operations on Matrices and Vectors

Command	Description
3 * x	Multiply every element of x by 3
x + 2	Add 2 to every element of x
x + y	Element-wise addition of two vectors x and y
A * y	Product of a matrix and vector
A * B	Product of two matrices
A .* B	Element-wise product of two matrices
A ^ 3	Square matrix A to the third power
A .^ 3	Every element of A to the third power
cos(A)	Compute the cosine of every element of A
abs(A)	Compute the absolute values of every element of A
A’	Transpose of A
inv(A)	Compute the inverse of A
det(A)	Compute the determinant of A
eig(A)	Compute the eigenvalues of A
size(A)	Get the size of A

Slicing Matrices and vectors

Command	Description
x(2:12)	The 2^nd to the 12^th elements of x
x(2:end)	The 2^nd to the last elements of x
x(1:3:end)	Every third element of x from the first to last
A(5,:)	Get the 5^th row of A
A(:,5)	Get the 5^th column of A
A(5, 1:3)	Get the first to third elements in the 5^th row

Constants

Command	Description
pi	$π$ = 3.141592653589793
NaN	Not a number (i.e. 0/0)
Inf	Infinity
realmax	Largest positive floating-point number $1.7977 x 10^{308}$
realmin	Smallest positive floating-point number $2.2251 x 10^{- 308}$

Loops

For loop:

for k = 1:5
    disp(k);
end

While loop:

k = 0;
while k < 7
    k = k + 1;
end

Logicals

a = 10
a == 5 % Test if a is equal to 5
    false
a == 10 % Test if a is equal to 10
    true
a >= 5 % Test if a is greater than or equal to 5
    true
a < 11 % Test if a is less than 11
    true
a ~= 4 % Test if a is not equal to 4
    true
a > 1 && a ~= 10 % Test if a is greater than 1 AND not equal to 10
    false
a > 1 || a ~= 10 % Test if a is greater than 1 OR not equal to 10
    true

Conditional Statements

if a > 10
    disp('Greater than 10');
elseif a == 5
    disp('a is 5');
else
    disp('Neither condition met');
end

Functions

function output = addNumbers(x, y)
    output = x + y;
end

addNumbers(10, -5)
    5

Plotting

Command	Description
plot(x,y)	Plot y versus x (must be the same length)
loglog(x,y)	Plot y versus x on a log-log scale (both axes have a logarithmic scale)
semilogx(x, y)	Plot y versus x with x on a log scale
semilogy(x, y)	Plot y versus x with y on a log scale
axis equal	Force the x and y axes to be scaled equally
title(‘A Title’)	Add a title to the plot
xlabel(‘x label’)	Add a label to the x axis
ylabel(‘y label’)	Add a label to the y axis
legend(‘foo’, ‘bar’)	Label 2 curves for the plot
grid	Add a grid to the plot
hold on	Multiple plots on single figure
figure	Start a new plot

Example:

x = linspace(-3*pi, 3*pi, 1000);
y1 = sin(x);
y2 = cos(x);

plot(x, y1, 'k-');  % Plot sin(x) as a black line
hold on             % Now we can add another curve
plot(x, y2, 'r-');  % Plot cos(x) as a red line

% Set the axis limits
axis([-3*pi, 3*pi, -1.5, 1.5])

% Add axis labels
xlabel('x');
ylabel('y');

% Add a title
title('A plot of cos(x) and sin(x)');

% Add a legend
legend('sin(x)', 'cos(x)');